1. Field of the Invention
The invention relates to the field of aircraft and, in particular, to a supersonic aircraft having reduced drag at supersonic speeds.
2. Description of Related Art
In the past the reduction in drag at supersonic speeds in aircraft has been made in small incremental steps, mostly in the form of refinements to the airfoil and center strut shape. However, over the years several patents have been issued indicating that substantial reductions in drag, along with a reduction in the sonic boom associated with supersonic flight could be dramatically reduced. The concept has been disclosed in U.S. Pat. No. 3,904,151, "Supersonic Upflow Wing"; U.S. Pat. No. 4,008,866, "Compression Energy Transformation System For A Supersonic Wing", U.S. Pat. No. 4,168,044; "Energy Conserving Supersonic Aircraft" U.S. Pat. No. 4,483,497, "Wide-Body Supersonic Aircraft", and U.S. Pat. No. 5,251,846 "Supersonic Aircraft Shock Wave Energy Recovery System", all by Scott C. Rethorst and incorporated herein by reference.
All these patents disclose the concept of using an airfoil having a generally concave downward or convex (cosine shaped) underside. A manifold is mounted under and aft of leading edge of the airfoil running over a substantial portion of its length. Bleed air from the engines is ejected out of a nozzle located at the trailing edge of the manifold forming a sheet of pressurized air on the underside of the airfoil. The interaction of the underside ambient air flow on the underside of the airfoil with the air ejected from the nozzle reflects the compression waves produced on the forward under wing back up to the aft underside of the airfoil. It appears that such action minimizes shock wave strength in the near field, improves the lift to drag ratio, and weakens the sonic boom signature. However, while the above referenced patents discuss the theory of operation in great length, none disclose, what is believed to be, a truly practical supersonic aircraft design utilizing this drag and sonic boom reduction concept. For example, the U.S. Pat. No. 4,483,497 patent discloses a rather conventional aircraft having a center strut, wings and twin rear mounted vertical stabilizers with a horizontal stabilizer therebetween. The manifold runs under the center strut from wing tip to wing tip. A manifold is also positioned under the horizontal stabilizer. Clearly very little thought has been given to transonic drag considerations as well as overall aerodynamic drag. In addition, no consideration has been given to applying the drag and sonic boom reduction concept to vertical surfaces such as the vertical stabilizer and the sides of the center strut.
Other patents of interest include U.S. Pat. No. 3,785,593 Aircraft Propulsion System" by H. J. P. Von Ohain, et al. in which a jet manifold is located under the wings of a conventional aircraft. However the jet manifold is used for VTOL and STOL type aircraft. In operation, the trailing edge wing flaps are extended and the jet manifold nozzle is rotated downward so as to increase the efficiency of the wing at low speeds. Also of interest are U.S. Pat. No. 4,019,699 "Aircraft Of Low Observability" by R. W. Wintersdorff, et al. which discloses a flying wing type aircraft; however neither incorporate shock suppression technology.
Thus it is a primary object of the subject invention to provide an improved supersonic aircraft.
It is another primary object of the subject invention to provide an improved supersonic aircraft with reduced drag at supersonic speeds.
It is a further object of the subject invention to provide improved supersonic speed that has reduced shock wave noise signature (sonic boom).